This invention relates to a lead frame having rows of leads thereon upon one end of which slit heads are mounted in opposing rows, or in a pair of transversely disposed pairs of rows, between which a space is provided for the reception of a semi-conductor device which comprises a suitable substrate upon which electronic circuits are imprinted either upon one or both faces thereof and to which leads are to be connected. When the semi-conductor devices are positioned between the heads on said rows of leads, soldering of the heads to the ends of the circuits on the substrate is effected.
Various problems have been encountered incident to the positioning of semi-conductor devices between opposite rows of leads and heads thereon and various attempts to solve said problems comprise the subject matter of the following patents:
U.S. Pat. No. 3,838,984--Crame et al Oct. 1, 1974 PA1 U.S. Pat. No. 4,109,096--Dehaine Aug. 22, 1978 PA1 U.S. Pat. No. 4,196,959--Chesemore et at Apr. 8, 1980 PA1 U.S. Pat. No. 4,234,666--Gursky Nov. 18, 1980 PA1 U.S. Pat. No. 4,323,293--DeRouen et al Apr. 6, 1982 PA1 U.S. Pat. No. 4,496,965--Orcutt et al Jan. 29, 1985
The present invention also is somewhat of a counterpart of applicant's prior pending application, U.S. Ser. No. 648,972, filed Sept. 10, 1984, now abandoned, and co-pending C.I.P. application, Ser. No. 010,297, filed Feb. 2, 1987, and offers certain improvements thereover without depreciating the subject matter of said prior applications, details of which are set forth below:
It is customary in furnishing lead frames to the industry requiring the same to arrange the same in strip form of indefinite length. The strips are formed from relatively thin sheet metal, one common form now employed being copper of a certain thickness and flexibility. In stamping thin metal strips of this type, such as to slit the heads on the end of leads and bend the legs of the heads apart, for example, to achieve a certain spacing between such legs, it is necessary to bend the legs apart slightly greater distance than is desired in order that the springiness of the material will tend to return the legs at least slightly toward the original position thereof and features of this type have to be taken into consideration incident to designing final products.